Meghan Markle sent out thank you cards following her birthday — and her choice of photo with commoners proves she's defying royal tradition

The duchess opted for a photo with her royal fans. Charles McQuillan/Getty Images

Meghan Markle sent out postcards to well-wishers following her 37th birthday.

The postcard featured a candid picture of the duchess laughing with royal fans, a departure from the standard posed photograph.

The Duke and Duchess of Cambridge have also been sending out thank you cards following Prince George's birthday and Prince Louis' christening.

Meghan Markle has sent a postcard to well-wishers following her 37th birthday, opting for a candid picture of her laughing with royals fans.

Kensington Palace sent out the notes, which feature a shot from Harry and Meghan's royal walkabout in Dublin, with the Duchess of Sussex beaming with delight as she accepts a bunch of flowers from a fan outside Trinity College.

The laid-back picture breaks tradition from typical royal postcards, which usually feature a posed photograph of the royals on their own or as a group, and not with members of the public.

One fan, known as loopycrown3, shared an image of the postcard on Instagram with the caption: "Thank you postcard from HRH the Duchess of Sussex thanking me for sending my birthday wishes."

The note from Meghan read: "The Duchess of Sussex is so touched you took the trouble to write as you did on the occasion of her 37th birthday.

"It really was most thoughtful of you and Her Royal Highness sends you her heartfelt thanks and best wishes."

One person said that Meghan is "a class act" for sending out the thank you notes in the comments.

Another said: "That's really lovely! What a great choice by The Duchess - spending time with the people."

The note is nearly identical to the message issued by the Duchess of Cambridge in previous years, although Meghan switched the word "heartfelt" for "warmest".

Meanwhile, the Duke and Duchess of Cambridge have been sending out thank you notes after their first-born, Prince George, turned five on July 22.

The royal couple chose the youngster's official birthday portrait for the postcard, shot by Matt Porteus on the day of his little brother Prince Louis' christening.

They also sent their thanks to all those who send their regards on Prince Louis' christening on July 9.

Their message read: "The Duke and Duchess of Cambridge were touched that you took the trouble to write on the occasion of the Baptism of their son, Prince Louis.

"Their Royal Highnesses are so grateful for all the wonderful, messages they have received and send you their warmest thanks and best wishes."

It was revealed last year that Kate and William send the same note to well-wishers, which send their "warmest thanks and best wishes", almost every time they send a thank you card.